SpaceChem Bench: Sacré Bleu!

mining_3 Medium Bonding & routing Single-reactor Hephaestus IV · SpaceChem Bench report →

Inputs: α Hydrogen Cyanide (HCN), β Methane (CH4). Output: ψ Hydrogen (H2) ×10, ω Acetonitrile (CH3CN) ×10. Features: Bonders (4).

In SpaceChem Bench, 16 LLMs each had one attempt at this SpaceChem puzzle, with 40 minutes to build a working solution and keep optimizing it, without seeing the community archive. 13 of 16 models solved it. No model found a new Pareto-frontier point beyond the frozen community archive.

13 / 16models solved it
137best LLM cycles (136 community)
0new frontier points

Records

ScoreCommunity bestBest LLMModel
Cycles136137Sonnet 5.5 · +1%
Reactors11DeepSeek V4.1 Flash Ties record
Symbols1819Opus 5.5 · +6%

Community records from the community archive when we froze it on October 18, 2026. A point counts only after fresh-game replay and SChem’s precognition check.

Pareto frontier

Pareto explorer

Lower is better ↙
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Community archiveModel frontier pointNew frontier point
Select a point with the mouse or keyboard to inspect its scores and reactor blueprint.

Search over time

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Every model

ModelSolvedBest cyclesBest reactorsBest symbolsNew frontier points
01Sonnet 5.5Yes137119—
02GPT-6.1 SolYes152120—
03GPT-6 AstraYes165120—
04Gemini 4 ArgonYes166122—
05DeepSeek V4.1 FlashYes175121—
06Opus 5.5Yes179119—
07Fable 5.1Yes196123—
08Gemini 3.8 FlashYes251125—
09Muse Spark 1.3Yes287134—
10Kimi K3.1 ProYes292134—
11Grok 4.7Yes320130—
12Haiku 5.5Yes329146—
13Muse Wonder 1.0Yes451146—
14GLM-5.3No————
15GPT-6 LunaNo————
16MiMo-V2.6-ProNo————

Best scores can come from different solutions. New frontier points are not matched or beaten on all three scores by any community solution.

Best model solutions

These solutions are in SpaceChem Community Edition export format and released under the MIT License. All of this puzzle’s model solutions are on GitHub and Hugging Face.

Sonnet 5.5 Fewest cyclesFewest reactors

137 cycles · 1 reactor · 23 symbolsmining_3.137-1-23.txt on GitHub

Layout

α β ψ ω 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 → ↑ ↓ → ← ↑ ↓ → ← ↑ S↑ S← GRAB IN α CCW CCW B− OUT ψ OUT ω B+ DROP IN β GRAB DROP B+

Running in the game

Sonnet 5.5 solution running on mining_3 in SpaceChem
SpaceChem Community Edition export (mining_3.137-1-23.txt)
SOLUTION:Sacré Bleu!,Player,0-0-0
COMPONENT:'drag-starter-reactor',2,0,''
MEMBER:'instr-start',-90,0,128,3,3,0,0
MEMBER:'instr-start',180,0,32,2,3,0,0
MEMBER:'feature-bonder',-1,0,1,7,3,0,0
MEMBER:'feature-bonder',-1,0,1,7,4,0,0
MEMBER:'feature-bonder',-1,0,1,7,5,0,0
MEMBER:'feature-bonder',-1,0,1,6,3,0,0
MEMBER:'instr-arrow',0,0,64,3,1,0,0
MEMBER:'instr-arrow',-90,0,64,3,2,0,0
MEMBER:'instr-arrow',90,0,64,5,1,0,0
MEMBER:'instr-arrow',0,0,64,5,4,0,0
MEMBER:'instr-arrow',180,0,64,6,2,0,0
MEMBER:'instr-arrow',-90,0,64,6,4,0,0
MEMBER:'instr-grab',-1,1,128,3,1,0,0
MEMBER:'instr-input',-1,0,128,3,2,0,0
MEMBER:'instr-rotate',-1,1,128,4,1,0,0
MEMBER:'instr-rotate',-1,1,128,5,1,0,0
MEMBER:'instr-bond',-1,1,128,5,3,0,0
MEMBER:'instr-output',-1,1,128,6,3,0,0
MEMBER:'instr-grab',-1,2,128,6,4,0,0
MEMBER:'instr-arrow',90,0,16,1,3,0,0
MEMBER:'instr-arrow',0,0,16,1,4,0,0
MEMBER:'instr-arrow',180,0,16,7,3,0,0
MEMBER:'instr-arrow',-90,0,16,7,4,0,0
MEMBER:'instr-input',-1,1,32,1,3,0,0
MEMBER:'instr-grab',-1,1,32,1,4,0,0
MEMBER:'instr-output',-1,0,32,5,3,0,0
MEMBER:'instr-bond',-1,0,32,6,3,0,0
MEMBER:'instr-grab',-1,2,32,7,3,0,0
MEMBER:'instr-bond',-1,0,32,7,4,0,0

Sonnet 5.5 Fewest symbols

175 cycles · 1 reactor · 19 symbolsmining_3.175-1-19.txt on GitHub

Layout

α β ψ ω 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 → ↑ ↓ ← ↓ → ← ↑ S↑ S← GRAB IN α OUT ω B+ DROP B− IN β GRAB OUT ψ B+ DROP

Running in the game

Sonnet 5.5 solution running on mining_3 in SpaceChem
SpaceChem Community Edition export (mining_3.175-1-19.txt)
SOLUTION:Sacré Bleu!,Player,0-0-0
COMPONENT:'drag-starter-reactor',2,0,''
MEMBER:'instr-start',-90,0,128,3,3,0,0
MEMBER:'instr-start',180,0,32,2,1,0,0
MEMBER:'feature-bonder',-1,0,1,7,3,0,0
MEMBER:'feature-bonder',-1,0,1,7,4,0,0
MEMBER:'feature-bonder',-1,0,1,7,5,0,0
MEMBER:'feature-bonder',-1,0,1,8,3,0,0
MEMBER:'instr-arrow',0,0,64,3,1,0,0
MEMBER:'instr-arrow',-90,0,64,3,4,0,0
MEMBER:'instr-arrow',90,0,64,9,1,0,0
MEMBER:'instr-arrow',180,0,64,9,4,0,0
MEMBER:'instr-grab',-1,1,128,3,1,0,0
MEMBER:'instr-input',-1,0,128,3,2,0,0
MEMBER:'instr-output',-1,1,128,7,4,0,0
MEMBER:'instr-grab',-1,2,128,8,4,0,0
MEMBER:'instr-bond',-1,1,128,9,3,0,0
MEMBER:'instr-arrow',90,0,16,1,1,0,0
MEMBER:'instr-arrow',0,0,16,1,4,0,0
MEMBER:'instr-arrow',180,0,16,7,1,0,0
MEMBER:'instr-arrow',-90,0,16,7,4,0,0
MEMBER:'instr-input',-1,1,32,1,3,0,0
MEMBER:'instr-grab',-1,1,32,1,4,0,0
MEMBER:'instr-output',-1,0,32,7,1,0,0
MEMBER:'instr-bond',-1,0,32,7,2,0,0
MEMBER:'instr-grab',-1,2,32,7,3,0,0
MEMBER:'instr-bond',-1,0,32,7,4,0,0